The present invention generally relates to the field of self-balancing scooters and more specifically to the field of control mechanisms for self-balancing scooters.
A self-balancing scooter (SBS) is a recreational transportation vehicle or device designed to carry a single passenger. Typically, an SBS has two wheels mounted symmetrically on either side of a center line of the scooter and having a common axis of rotation. Each wheel is independently driven, and steering is accomplished by differential speed control of the two wheels.
One type of SBS has a unitary body with a footrest on which the passenger/rider stands. An example is shown in U.S. Pat. No. 6,302,230 and available as the “Segway®” from SEGWAY, INC., 14 Technology Drive, Bedford, N.H. 03110. This form of SBS is speed-controlled by tilting the body forward or backward, and it is steered by differentially increasing the speed of an “outside” wheel relative to an “inside” wheel. In the Segway “PT” device this differential speed control is accomplished by moving a “LeanSteer Frame”, essentially a handle bar support shaft, to the left or right.
Another type of SBS employs a split body with mirror-image left and right halves, with each half having a drive wheel located on a common axis outboard of the rider's feet. An example of such an SBS is disclosed in U.S. Pat. No. 8,738,278 and is known colloquially as a “hoverboard”. The left and right halves are rotationally coupled to each other, allowing relative rotation of approximately plus or minus 5° in the forward/backward direction. Each half of the hover board has its own motorized and servo controlled drive wheel for propulsion. Each wheel is driven by a brushless DC motor, controlled by rotational inputs that the rider makes to each half of the hoverboard by tilting his or her feet forward or backwards. When the feet are tilted in unison, the hoverboard moves forward or backwards in a straight line; when the feet are tilted at different angles, the hoverboard turns in the direction of the less-forward-tilted foot. If the feet are tilted by the same angle but in opposing directions, the hoverboard rotates about a vertical axis.